The engineering of thermostable enzymes is receiving increased attention. The paper, detergent, and biofuel industries, in particular, seek to use environmentally friendly enzymes instead of toxic chlorine chemicals. Enzymes typically function at temperatures below 60°C and denature if exposed to higher temperatures. In contrast, a small portion of enzymes can withstand higher temperatures as a...

The significance of subunit interface residues Arg49 and Lys50 in the function of porcine liver fructose-1,6-bisphosphatase was explored by site-directed mutagenesis, initial rate kinetics, and circular dichroism spectroscopy. The Lys50 --> Met mutant had kinetic properties similar to the wild-type enzyme but was more thermostable. Mutants Arg49 --> Leu, Arg49 --> Asp, Arg49 --> Cys were less t...

BACKGROUND Thermostable enzymes from thermophilic microorganisms are playing more and more important roles in molecular biology R&D and industrial applications. However, over-production of recombinant soluble proteins from thermophilic microorganisms in mesophilic hosts (e.g. E. coli) remains challenging sometimes. RESULTS An open reading frame TM0438 from a hyperthermophilic bacterium Thermo...

A thermostable pullulanase (alpha-dextrin 6-glucanohydrolase [EC 3.2.1.41]) from a newly isolated Bacillus stearothermophilus strain (TRS128) was purified and characterized. The enzyme hydrolyzed (1-->6)-alpha-d-glucosidic linkages of pullulan to produce maltotriose, and the optimum temperature was 65 degrees C. About 90% of the enzyme activity was retained after treatment at 65 degrees C for 6...

Some general and physical properties and the’ amino acid composition of the thermostable cr-amylase of Bacillus sbarothermophilus have been described in previous papers (l-3). In an effort to further correlate the thermostability of this enzyme with its molecular organization, a study of the structure of this protein has been undertaken. In this paper are reported the results of an investigatio...

To study the effect of inserted peptides on the secretion and processing of exported proteins in Bacillus subtilis and Escherichia coli, pBR322-derived DNA fragments coding for small peptides were inserted between the DNA coding for the 31 amino acid B. subtilis alpha-amylase signal peptide and that coding for the mature part of the extracellular thermostable alpha-amylase of B. stearothermophi...

Thermostable α-amylases hold a very important place in commercial industrial applications Sri Lanka. Therefore, the main aim of this study was to identify superior Bacillus strain and optimize growth conditions that could yield high α-amylase production. Three strains, B. amyloliquefaciens ATCC 23350, licheniformis 14580 megaterium 14581 were used for study. Shake flask culture experiments cond...

Actinomycetes are an uncommon agent of human infections and its pathogenic factors are not known. The present study reports a rare case isolation of an actinomycete from a woman pleural fluid; the strain was identified by 16S rRNA gene sequence analysis. This strain was tested to produce an extracellular protease that hydrolysis gelatin, casein and hemoglobin on agar mediums. The purification o...

Thermostable α-amylase is of great importance in the starch fermentation industry; it is extensively used in the manufacture of beverages, baby foods, medicines, and pharmaceuticals. Bacillus amyloliquefaciens produces thermostable α-amylase; however, production of thermostable α-amylase is limited. Ion-beam implantation is an effective method for mutation breeding in microbes. We conduct...

Thermostabilities of kanamycin nucleotidyltransferase and of its mutants that became thermostable, in the free state, because of single-amino-acid replacements were studied after immobilization of the enzymes on cyanogen bromide-activated Sephadex G-200 particles. Lys in place of Gln at position 102 decreased the thermostability of the immobilized enzyme, whereas replacement with other amino ac...